S-LAL14 by Ohara

$$n(\lambda) = \sqrt{1 + \frac{1.23721\,\lambda^2}{\lambda^2 - 0.0153551} + \frac{0.589723\,\lambda^2}{\lambda^2 - -0.000307896} + \frac{1.31922\,\lambda^2}{\lambda^2 - 93.7203}}$$

$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[3.12 \times 10^{-6} + 2(1.19 \times 10^{-8})\,\Delta T + 3(2.67 \times 10^{-12})\,\Delta T^2 + \frac{4.01 \times 10^{-7} + 2(8.06 \times 10^{-10})\,\Delta T}{\lambda - 0.216}\right] \Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$